Dual functional performance of fiber Bragg gratings coated with metals using flash evaporation technique

Metallic and other type of coatings on fiber Bragg grating (FBG) sensors alter their sensitivity with thermal and mechanical stress while protecting the fragile optical fiber in harsh sensing surroundings. The behavior of the coated materials is unique in their response to thermal and mechanical stress depending on the thickness and the mode of coating. The thermal stress during the coating affects the temperature sensitivity of FBG sensors. We have explored the thermal response of FBGs coated with Al and Pb to an average thickness of 80 nm using flash evaporation technique where the FBG sensor is mounted in a region at room temperature in an evacuated chamber having a pressure of 10^?6 Torr which will minimize any thermal stress during the coating process. The coating thickness is chosen in the nanometer region with the aim to study thermal behavior of nanocoatings and their effect on FBG sensitivity. The sensitivity of FBGs is evaluated from the wavelengths recorded using an optical sensing interrogator sm 130 (Micron Optics) from room temperature to 300 °C both during heating and cooling. It is observed that the sensitivity of the metal coated fibers is better than the reference FBG with no coating for the entire range of temperature. For a coating thickness of 80 nm, Al coated FBG is more sensitive than the one coated with Pb up to 170 °C and it reverses at higher temperatures. This point is identified as a reversible phase transition in Pb monolayers as the 2-dimensional aspects of the metal layers are dominant in the nanocoatings of Pb. On cooling, the phase transition reverses and the FBGs return to the original state and for repeated cycles of heating and cooling the same pattern is observed. Thus the FBG functions as a sensor of the phase transitions of the coatings also.     

Effect of rotation of feed and seed rods on the quality of Na0.75CoO2 single crystal grown by traveling solvent floating zone method

High purity Na_0.75CoO₂ single crystals have been grown by floating zone method. We found the rotation of feed and seed rods play a crucial role in growing high quality single crystal. Systematic investigations suggest the occurrence of a phase separation at microscopic level, such as the separation into Na-rich and Na-poor domains during the growth, and formation of impurity phase(s) depending on growth conditions. Na_xCoO₂ (x = 0.30, 0.60) crystals have been prepared by sodium deintercalation from Na_0.75CoO₂. Powder X-ray and energy dispersive X-ray analyses have confirmed the phase purity and homogeneity of the samples. Magnetic susceptibility measurements of x = 0.60 and 0.75 crystals indicate a bulk phase transition at 22 K and an anomaly around 339 K and 334 K respectively which are attributed to structural transition. In addition some unique features related to Na_0.60CoO₂ were observed.     

Introduction and expression of the cry1Ac gene of Bacillus thuringiensis in a cereal-associated bacterium, Bacillus polymyxa

The abilities of Bacillus polymyxa and Bacillus thuringiensis to survive on the rice phyllospere were compared; it was found that B. polymyxa colonizes the crop better. This study also showed that B. polymyxa inoculation to rice plants increased the shoot and the root growth of the crop. Efforts were made to introduce the cry1Ac gene of B. thuringiensis subsp. kurstaki into B. polymyxa so that the application of such transgenic B. polymyxa strains would prove to be dually beneficial to rice crops both as a biopesticide and as a biofertilizer. Immunoblot analysis of the recombinant organism containing the cry1Ac gene, strain BP113, indicated efficient expression of this gene in the heterologous host. Bioassays with the first instar larvae of the yellow stem borer of rice (Scirpophaga incertulas) revealed that the protein preparations from BP113 were toxic.     

HIV infection amongst leprosy patients in south India

We use the trapezoidal lamellar incision as standard construction for sutureless self-sealing wound closure in our clinic: a 7 mm incision for phacoemulsification and implantation of a 6.5 mm optic diameter PMMA posterior chamber less (PCL) and an incision up to 11 mm for ECCE with standard PCL. The operation can be performed in a nearly closed system because of the self-sealing wound construction. Experiments in cadaver eyes showed that the wound closure of a 7 mm incision with the no-stitch technique ruptured at a pressure five times greater than the cross-stitch-sutured corneoscleral incision and in an 11 mm incision four times greater (602 +/- 149 mmHg and 150 +/- 29 mmHg). Due to the high stability of the wound closure, no sutures are necessary. Complications arising in connection with sutures are therefore avoided. Clinically, two typical postoperative complications were observed: hypotony occurred in 1% and anterior chamber hemorrhage in 5%. These complications are exclusively caused by imperfection of the internal corneal opening.     

Heuristics for operator allocation and sequencing in just-in-time flow line manufacturing cell

Group technology tries to exploit the similarity between parts and machines and forms machine groups and part families. Just-in-time production tries to manufacture the parts whenever required there by reducing the inventory and eliminating waste.

In order to apply JIT in a GT cell, the cell is divided into modules and parts move from one module to another in small transfer batches. This paper addresses the problem of operator allocation for the modules and sequencing the variety of parts with the objective of minimizing the makespan.

Six different methodologies have been presented and the results compared in terms of makespan and computational time.     

Solution NMR of polypeptides hyperpolarized by dynamic nuclear polarization

Hyperpolarization of nuclear spins through techniques such as dynamic nuclear polarization (DNP) can greatly increase the signal-to-noise ratio in NMR measurements, thus eliminating the need for signal averaging. This enables the study of many dynamic processes which would otherwise not be amenable to study by NMR spectroscopy. A report of solid- to liquid-state DNP of a short peptide, bacitracin A, as well as of a full-length protein, L23, is presented here. The polypeptides are hyperpolarized at low temperature and dissolved for NMR signal acquisition in the liquid state in mixtures of organic solvent and water. Signal enhancements of 300-2000 are obtained in partially deuterated polypeptide when hyperpolarized on (13)C and of 30-180 when hyperpolarized on (1)H. A simulated spectrum is used to identify different resonances in the hyperpolarized (13)C spectra, and the relation between observed signal enhancement for various groups in the protein and relaxation parameters measured from the hyperpolarized samples is discussed. Thus far, solid- to liquid-state DNP has been used in conjunction with small molecules. The results presented here, however, demonstrate the feasibility of hyperpolarizing larger proteins, with potential applications toward the study of protein folding or macromolecular interactions.     

Synthesis of tungsten oxide (W18O49) nanosheets utilizing EDTA salt by microwave irradiation method

We report the synthesis of crystalline W₁₈O₄₉ with nanosheet like morphology by low cost microwave irradiation method without employing hydrothermal process for the first time. Initially, WO₃·H₂O was synthesized using ethylenediaminetetraacetic acid (EDTA) as surface modulator. The product was annealed at 600 °C for 6 h in ambient atmosphere in order to obtain anhydrous tungsten oxide W₁₈O₄₉. Powder X-ray diffraction results confirmed the as prepared WO₃·H₂O to be orthorhombic and W₁₈O₄₉ to be monoclinic phase, respectively. Transmission electron micrographs (TEM) revealed that the W₁₈O₄₉ nanosheets have the average dimensions of the order of 250 nm in length and around 150 nm in width. UV-visible diffusion reflectance spectroscopic (DRS) studies revealed the band gap energies to be 3.28 and 3.47 eV for WO₃·H₂O and W₁₈O₄₉ samples, respectively. The growth mechanism of two dimensional W₁₈O₄₉ nanosheets is discussed.     

Inhibition study of Erioglaucine disodium salt on carbon steel in hydrochloric acid medium using weight loss,electrochemical and thermodynamic properties

The corrosion inhibitory action of Erioglaucine disodium salt (EDS) on carbon steel in acid medium was evaluated by weight loss measurement, impedance and polarization studies. The increased inhibitory action against corrosion in the presence of inhibitor with increased of Erioglaucine disodium salt concentration. The effect of concentration and temperature studies were performed on the inhibition effect. The adsorption efficiency of Erioglaucine disodium salt was corroborated with high capacitive loop of Nyquist plot. The polarization behavior of Erioglaucine disodium salt concentration has been recorded showed it behaved as mixed type nature in acid medium. The enhancement in the inhibition action on the carbon steel has increased with increasing inhibitor concentration. The Langmuir adsorption isotherm gave information about the adsorption mode with carbon steel. Thermodynamic properties (ΔS¹, ΔH¹, ΔG° and E_a) of the Erioglaucine of the adsorption reaction were measured from the temperature effect. The hydrogen gas evolution measurement showed the strong adsorption nature of the inhibitor with the metal surface. The surface protection effect of Erioglaucine disodium salt on the carbon steel has studied with SEM and FTIR analysis.     

ANN Model to Predict Fracture Characteristics of High Strength and Ultra High Strength Concrete Beams

This paper presents fracture mechanics based Artificial Neural Network (ANN) model to predict the fracture characteristics of high strength and ultra high strength concrete beams. Fracture characteristics include fracture energy (Gf), critical stress intensity factor (KIC) and critical crack tip opening displacement (CTODc). Failure load of the beam (Pmax) is also predicated by using ANN model. Characterization of mix and testing of beams of high strength and ultra strength concrete have been described. Methodologies for evaluation of fracture energy, critical stress intensity factor and critical crack tip opening displacement have been outlined. Back-propagation training technique has been employed for updating the weights of each layer based on the error in the network output. Levenberg- Marquardt algorithm has been used for feed-forward back-propagation. Four ANN models have been developed by using MATLAB software for training and prediction of fracture parameters and failure load. ANN has been trained with about 70% of the total 87 data sets and tested with about 30% of the total data sets. It is observed from the studies that the predicted values of Pmax, Gf, failure load, KIc and CTODc are in good agreement with those of the experimental values.     

Anti-Obesity Efficacy of Pediococcus acidilactici MNL5 in Canorhabditis elegans Gut Model

In the present study, thirty two lactic acid bacteria (LAB) were isolated from fermented Indian herbal medicine. In comparison to other strains, MNL5 had stronger bile salt hydrolase (BSH) and cholesterol-lowering properties. Furthermore, it can withstand the extreme conditions found in the GI tract, due to, e.g., pepsin, bile salts, pancreatin, and acids. Pediococcus acidilactici MNL5 was identified as a probiotic candidate after sequencing the 16S rRNA gene. The antibacterial activity of P. acidilactici MNL5 cell-free supernatants (CFS) against Escherichia coli, Staphylococcus aureus, Helicobacter pylori, Bacillus cereus, and Candida albicans was moderate. A Caenorhabditis elegans experiment was also performed to assess the effectiveness of P. acidilactici MNL5 supplementation to increase life span compared to E. coli supplementation (DAF-2 and LIU1 models) (p < 0.05). An immense reduction of the lipid droplets of C. elegans was identified through a fluorescent microscope. The drastic alteration of the expression of fat genes is related to obesity phenotypes. Hence, several paths are evolutionary for C. elegans; the results of our work highlight the nematode as an important model for obesity.